MATH SOLVE

5 months ago

Q:
# A journal article reports that a sample of size 5 was used as a basis for calculating a 95% CI for the true average natural frequency (Hz) of delaminated beams of a certain type. The resulting interval was (230.061, 233.807). You decide that a confidence level of 99% is more appropriate than the 95% level used. What are the limits of the 99% interval?

Accepted Solution

A:

Answer:(229.5450, 234. 3230)Step-by-step explanation:Given that a journal article reports that a sample of size 5 was used as a basis for calculating a 95% CI for the true average natural frequency (Hz) of delaminated beams of a certain type.95% confidence interval was[tex](230.061, 233.807)\\[/tex]From confidence interval we find mean as the average of lower and upper bound.Mean = [tex]\frac{463.868}{2} \\=231.934[/tex]Margin of error = upper bound -mean=[tex]1.873[/tex]i.e. 1.96 * std error = 1.873For 99% interval margin of error would be 2.58*std errorso margin of error for 99% = [tex]2.58*\frac{1.873}{1.96} \\=2.3890[/tex]Confidence interval 99% lower bound = Mean - 2.3890 =229.5450Upper bound = Mean +2.3890 = 234.3230